Many people use mobile stations, such as cell phones and personal digital assistants, to communicate with cellular wireless networks, which typically provide communication services such as voice, text messaging, and packet-data communication. These mobile stations and networks typically communicate with each other over a radio frequency (RF) air interface according to a wireless protocol. Mobile stations typically conduct wireless communications with one or more base stations, each of which are arranged to send communications to and receive communications from mobile stations over the RF air interface.
As a mobile station moves between coverage areas or when network conditions change or for other reasons, the mobile station may request to be “handed off” from operating in one coverage area to operating in another coverage area.